As Internet usage continues to increase so has the demand for rapidly channeling vast amounts of data. Because the majority of the data sent over the Internet is encoded in optical signals, surfing the Internet requires rapidly channeling optical signals from one optical fiber to another. In the past, this was accomplished at network hubs using electronic switches where optical signals were converted into electrical signals that were subsequently switched around electronically followed by converting the electrical signals back into optical signals to continue the journey. However, electronic switches were not up to the task of meeting future Internet demand, because the switches are bulky, slow, and require large amounts of power.
In recent years, this electronic bottleneck has, in part, been diminished with the introduction of optical switches. One example of an optical switch is implemented with micro-electromechanical systems (“MEMS”) technology. The ends of hundreds of incoming and outgoing optical fibers are capped with tiny lenses and mounted as an array in a surface of an optical switch assembly. The optical switch includes an array of MEMS micromirrors that faces the array of lenses and a mirror with a fixed orientation. Each micromirror is electronically controlled and can be independently reoriented. An optical signal enters the optical switch through an input optical fiber, where it bounces off a micromirror oriented to reflect the optical signal off of the fixed mirror toward another micromirror oriented to direct the optical signal into an output optical fiber. The micromirrors can be electronically reoriented on the order of milliseconds, enabling rapid switching of optical signals from input to output optical fibers without having to engage in the time and energy consuming process of converting the optical signals into electrical signals and back into optical signals. For example, an array of 256 micromirrors can be fabricated on less than one square inch of silicon. This compact array of micromirrors implemented in an optical switch provides greater than 32 times more switching density than a comparable electronic switch, and with no optical-electrical-optical conversion, the optical switch provides up to a 100-fold reduction in power consumption.
Although, many existing optical switches provide rapid switching of optical signals, data centers and the telecommunications industry continue to seek faster and more energy efficient optical switches to handle the ever increasing demand for rapidly channeling data in data centers and over the Internet.